Nitration of sugars and their glycosides



Patented Oct. 5, 1937 5. QFFICE NITRATION F SUGARS AND THEIR GLYCOSIDESJoseph A.- Wyler, Allentown, Pa., assignor to Tro- .ian Powder Company,a corporation of New York No Drawing. Application June 17, 1935,

Serial No. 27,049

22 Claims. (Cl. 260-145) My invention relates to improvements in thenitration of sugars and their glycosides, and more particularlyrelatesto improved means for bringing about the nitration of sugars suchas cane sugar, glucose, levulose, lactose, and the like, or theglycosides thereof, with the production of products having satisfactoryphysical characteristics and also having satisfactory chemicalcharacteristics particularly with reference to stability. One of theobjects of my invention is to provide improved means for the nitrationof the various sugars and their glycosides, and another of the objectsof my invention is to provide improved means for the preparation of thenitrated sugars and their glycosides in Very pure condition. Thisapplication is a continuation in part of my application S. N. 728,679,filed June 2, 1934.

My present invention rests upon my discovery that the nitrated esters ofcertain hydroxy acids dissolve nitrated sugar readily and produce mix-'tures which may contain as much as 70% of nitrated sugar, while stillhaving such physical characteristics as will permit them to be purifiedand stabilized by known washing and stabilizing methods. glucose,levulose, lactose, etc. are nitrated by the ordinary methods known up tothis time, thick, gummy, pasty or very viscous nitrated products areobtained which are very difficult to purify and to stabilize. If suchagents as glycerin, glycols, and chlorhydrins are used as partialsolvents, thick solutions are obtained which, if they contain more than25% of nitrated sugar, are too viscous to be treated by the usualwashing and stabilizing methods.

As examples of the nitrated esters which I may employ in the practice ofmy present invention I will mention nitrated methyl glycollate, nitratedethyl glycollate, nitrated propyl glycollate, nitrated butyl glycollate,nitrated amyl glycollate, nitrated methyl lactate, nitrated ethyllactate, nitrated propyl lactate, nitrated butyl lactate, nitrated amyllactate, nitrated methyl tartronate, nitrated ethyl tartronate, nitratedmethyl malate, nitrated ethyl malate, nitrated dimethyl tartrate,nitrated diethyl tartrate, and the higher homologues. When the purposeof the work is to prepare the crystalline sugar nitrate I find the useof nitrated butyl lactate is particularly advantageous.

The nitrated esters may be used either directly as such, or they may beproduced in the same nitration operation as is the nitrated sugar or thenitrated glycoside, by the addition or the esters to the nitrationmixture.

It is well known that when cane sugar,

As sugars to be used in the procedure of my invention, I may use canesugar, glucose, lactose, levulose, etc. and as glycosides, I may usemethyl glucoside, ethyl glucoside, methyl lactoside, ethyl lactoside,etc. 5

As examples of the application of my present invention, for the purposeof illustrating its general features, I give the following:

Example 1.To 990 parts of mixed acid consisting of 40% H2SO4 and 60%HNOa add 60 parts of dibutyl tartrate, keeping the temperature below 30G. Then add 60 parts of powdered cane sugar, maintaining the temperaturebelow 30 C., and preferably below 20 C. Stir continuously-throughout thenitration.

At the completion of the nitration the nitration mixture is settled andthe solution of nitrated sugar in the dinitrated butyl tartrate formsthe upper layer. The latter is separated, washed in dilute alkali,stabilized and settled or filtered to remove moisture and mechanicalimpurities.

Example 2.--To 150 parts of 98% ENG: cooled to below 20 0., add 20 partsof methyl glucoside with constant stirring and cooling. Then add 20parts of butyl lactate, keeping the temperature below 20 G. Then add 200parts of 105% oleum to complete the nitration and to cause a separationof the nitrated products as a solution floating upon the spent acid. Theseparated nitrated glucoside solution is then washed, neutralized,

stabilized and settled or filtered to remove moisture and mechanicalimpurities.

Example 3.-108 parts of ethyl lactate are run into 1126 parts of a mixedacid consisting of 40% H2SO4 and 60% I-INOs mantained at a temperaturebelow 30 C. Thenadd 80 parts of cane sugar, a littleat a time, keepingthe tem perature below 25 C. and preferably lower than 10 C. Thenitration mixture is then allowed to stand, when separation into twolayers will occur. The upper layer is the nitrated product and can bereadily separated, and should then be washed, filtered and neutralizedaccording to the methods well known in the art.

Example 4.1126 parts of a mixed acid con- 'sisting of I-INOs and 40%H2804 are placed time of nitration is often about four hours.

The nitrated charge is then run to a settler where the mixture separatesinto two layers. The lower layer is' the spent acid and contains only a'small amount of nitrated products. The upper layer consists of thenitrated ethyl lactate and nitrated sugar. At times this upper layer hasa small amount of crystalline nitrated sugar suspended in it. c

The upper layer is then drowned intap water,

Washed, neutralized by stirring in 2% sodium bicarbonate, washed withwater and allowed to settle. The lower layer is a mixture of nitratedethyl lactate and sucrose nitrate'with some occluded Water. By settlingovernight only a small amount of water remains in suspension.

This lower layer is then treated with .ethyl alcohol, while the mixtureis being stirred untila crystalline precipitate of sucrose octonitrateseparates. Only enough alcohol is added to cause this precipitation.'The'mixture is filtered, the precipitate is washed with alcohol anddried at about 40 C. The yield of crystals is about 145 parts; i r

Example 5.-l126 parts of a'mixed acid con- ,sisting 01 .5% nitric acidand 50% sulfuric acid and 5%. water are placed in a suitable nitratingvessel and cooled to about 0 0. Then, with continued stirring andcooling, add 108 parts of nitrated butyl lactate. When all thenitrated'butyl lactate has been added, add parts of powdered driedsucrose, maintaining the temperature around 0 C. The stirring andcooling is continued for about one hour after the feeding of the sugarin order to complete the nitration. V

The nitrated'charge is handled in the'manner as described in Example 4.

Insteadof drowning the nitrated sugar mixture in water, and thereafterextracting the nitrated mixture with a solvent, it is of course possibleto drown the. nitrated sugar mixture directly in a mixture of ethylalcohol and a hydrocarbon to obtain directly, the precipitatedcrystalline nitrated sugar. w

While the above examples represent preferred methods'of nitration,itshould be noted that I do not confine myself to these narrowlimits.The characteristic'part of my invention'is the pres ence of a nitratedester of a'hydr'oxy acid in'the nitration mixture at the time of theseparation of the nitrated sugar or glycoside from the spent acid,and'it will readily be understood that I may vary the strengths andproportions of acids, the temperatures of the components and thetemperature of nitration, the ratio of nitrated ester to sugar or toacids, the order ofxadditionqof materials to be nitrated, etc. withoutdeparting from the essence of this invention.

I have discovered that when a sugar is nitrated in the presence of anitrated hydroxy acid the resulting nitrated mixture is capable of beingseparated to give the pure nitrated sugars in higher purity and inbetter yield than can be obtain'edby methods previously known, and thiscan beaccomplished without the use of repeated extractions orfracticnations. I' have discovered, for example, that thenitrationproducts made in accordance with my present'invention may be extractedwith such solvents as ethyl alcohol or propyl alcohol, or with suchsolvents as propane, butane, heptane, pentane, hexane,benzene, orordinary commercial gasoline, or with mixed solvents such as pentane,hexane, etc. with chloroform or carbon tetrachloride, or withmfixed inorder to complete the nitration. The total solvents such as analcohol'anda chlorinated hydrocarbon, all of these solvents and solventmixtures possessing. greater solvent action for the V nitratedhydroxyacid esters than they do for the sucrose octonitrate in the formof crystals from the nitration mixture of nitrated butyl lactate ,andcane sugar," without any recrystallization whatever, using in this caseeither ethyl alcohol or pentane as the differential solvent fordissolving the nitrated hydroxy acid ester and thus sep arating it fromthe insoluble nitrated sugar, and that these crystalsQbya simplestabilizing treatment such as stirring them in a two percent solution ofbicarbonateof soda, or'by first stirring them in a two percent solutionof bicarbonate of soda, and thereafter washing them in a one percentsolution of ammonia, maybe obtained as the pure sucrose octonitratehaving substantially the theoretical nitrogen content, and possessingsubstantially the same stability as the sucrose octoni trate previouslyobtained as the result of extensive recrystallization and stabilizationtreatments.

As many modifications may be made within the limits of the disclosure ofmy invention as herein set forth, it is to be understood that theexamples herein given are for purposes of illustration and the figurestherein given are not to be considered as limitations, and nolimitations should be placed upon the scope of my invention except suchas are indicated in the appended claims.

I claim: 1

l. The process of nitrating a member of the group consisting of a sugarand a sugar glycoside in the presence'of a nitrated alkyl ester of asaturated hydroxy aliphatic carboxylic acid, said car'- boxylic acidcontaining not more than two carboxyl groupsr V 2..The process ofnitrating cane sugar in the presence of a nitrated alkyl ester of asaturated hydroxy'aliphaticicarboxylic acid, said carboxylic acidcontaining not more than two carboxyl groups. r

3. The process the-presence of a nitrated alkyl ester of a,saturated'hydroxy aliphatic carboxylic acid, said carboxylie acidcontaining not'mo're than two car boxyl groups 4. The p-rocess ofnitratin g a sugarin the presence of a member of the group consisting ofnitrated methyl glycollate, nitrated ethyl glycollate, nitrated propylglycollate, nitrated butyl glycollate, nitrated .amyl glycollate,nitrated methyl lactate, nitrated ethyl lactate; nitrated propyl lactatenitrated butyl lactate, nitrated amyl lactate, nitrated methyltartronate, nitrated ethyl tartronate, nitrated ethyl malate,"nitrateddimethyl tartr'ate and nitrated diethyl tartrate.

5. The process of nitrating glucose in the presenceof a member ofthe'groupoonsisting of nirated methyl glycollate, nitrated ethylglycollate,

of nitrating methyl glucoside in nitrated propyl .glycollate, nitratedbutyl glycollycollate, nitrated propyl glycollate, nitrated butylglycollate, nitrated amyl glycollate, nitrated 7 methyl lactate,nitrated ethyl lactate, nitrated propyl lactate, nitrated butyl lactate,nitrated amyl lactate, nitrated methyl'tartronate, nitrated ethyltartronate, nitrated ethyl malate, nitrated dimethyl tartrate andnitrated diethyl tartrate.

'7. The process of nitrating a sugar which corn;- prises the addition ofthe sugar and of the alkyl ester of a saturated hydroxyaliphatic-carboxylic acid containing not more thg'an two carboxylgroups, to a nitrating acid and the separation of the products ofnitration from the spent acid.

8. The process of nitrating cane sugar which comprises the addition ofan alkyl ester of a saturated hydroxy aliphatic carboxylic acidcontaining not more than two carboxyl groups, to a mixed acid consistingof approximately 60% HNOs and 40% H2804 followed by the addition of thecane sugar, maintaining the temperature of the mixture below 30 C. andseparating nitrated products from the spent acid. I

9. The process of nitrating cane sugar which comprises the addition ofethyl lactate to a mixed acid consisting of approximately 60% HNO3 and40% H2SO4 followed by the addition of the cane sugar, maintaining thetemperature of the mix ture below 30 C. and separating nitrated productsfrom the spent acid.

10. The process of nitrating a sugar which comprises the addition of thesugar and the alkyl ester of a saturated hydroxy aliphatic carboxylicacid containing not more than two carboxyl groups, to a nitrating acid,the separation of the products of nitration from the spent acid, thedrowning cf the nitrated sugar-nitrated hydroxy acid ester mixture inWater, the separation of the nitrated sugar-nitrated hydroxy acid estermixture from the excess of water, and the solution of the nitratedhydroxy acid ester in a solvent in which nitrated sugar is substantiallyinsoluble.

11. The process of nitrating cane sugar which comprises the addition ofthe sugar and the alkyl ester of a saturated hydroxy aliphaticcarboxylic acid containing not more than two carboxyl groups, to anitrating acid, the separation of the products of nitration from thespent acid, the drowning of the nitrated sugar-nitrated hydroxy acidester mixture in water, the separation of the nitrated sugar-nitratedhydroxy acid ester mixture from the excess of water, and the solution ofthe nitrated hydroxy acid ester in a solvent in which nitrated sugar issubstantially insoluble.

12. The process of nitrating glucose which comprises the addition of thesugar and the alkyl ester of a saturated hydroxy aliphatic carboxylicacid containing not more than two carboxyl groups, to a nitrating acid,the separation of the products of nitration from the spent acid, thedrowning of the nitrated sugar-nitrated hydroxy acid ester mixture inwater, the separation of the nitrated sugar-nitrated hydroxy acid estermixture from the excess of water, and the solution of the nitratedhydroxy acid ester in a solvent in which nitrated sugar is substantiallyinsoluble.

13. The process of nitrating methyl glucoside which comprises theaddition of the sugar and the alkyl ester of a saturated hydroxyaliphatic carboxylic acid containing not more than two carboxyl groups,to a nitrating acid, the separation of the products of nitration fromthe spent acid, the drowning of the nitrated sugar-nitrated hydroxy acidester mixture in water, the separation of the nitrated sugar-nitratedhydroxy acid ester mixture from the excess of water, and the solution ofthe nitrated hydroxy acid ester in a solvent in which nitrated sugar issubstantially insoluble. I

14. The process of nitrating a sugar which comprises the addition of thesugar and the alkyl ester of a saturated'hydroxy aliphatic carboxylicacid containing not more than two carboxyl groups, to a nitrating acid,the separation of the products of nitration from the spent acid, thedrowning of the nitrated sugar-nitrated hydroxy acid ester mixture inwater, and the solution of the nitrated hydroxy acid ester in a solventselected from the group of ethyl alcohol, propyl al- .cohol, propane,butane, pentane, benzene, gasoline, hexane, heptane, carbontetrachloride and chloroform.

15. The process of nitrating cane sugar which comprises the addition ofthe sugar and the alkyl ester of a saturated hydroxy aliphaticcarboxylic acid containing not more than two carboxyl groups, to anitrating acid, the separation of the products of nitration from thespent acid, the drowning of the nitrated sugar-nitrated hydroxy acidester mixture in water, and the solution of the nitrated hydroxy acidester in a solvent selected from the group of ethyl alcohol, propylalcohol, propane, butane, pentane, benzene, gasoline, hexane, heptane,carbon tetrachloride and chloroform.

16. The process of nitrating glucose which com prises the addition ofthe sugar and the alkyl ester of a saturated hydroxy aliphaticcarboxylic acid containing not more than two carboxyl groups, to anitrating acid, the separation of the products of nitration from thespent acid, the drowning of the nitrated sugar-nitrated hydroxy acidester mixture in water, and the solution of the nitrated hydroxy acidester in a solvent selected from the group of ethyl alcohol, propylalcohol, propane, butane, pentane, benzene, gasoline, hexane, heptane,carbon tetrachloride and chloroform.

1'7. The process of nitrating methyl glucoside which comprises theaddition of the glucoside and the alkyl ester of a saturated hydroxyalie phatic carboxylic acid containing not more than two carboxylgroups, to a nitrating acid, the separation of the products of nitrationfrom the spent acid, the drowning of the nitrated sugarnitr'ated hydroxyacid ester mixture in water,

and the solution of the nitrated hydroxy acid ester in a solventselected from the group of ethyl a1- cohol, propyl alcohol, propane,butane, pentane, benzene, gasoline, hexane, heptane, carbontetrachloride and chloroform.

18. The process of nitrating a sugar in the presence of a nitrated alkylester of a saturated hydroxy aliphatic carboxylic acid, said carboxylicacid containing not more than two carboxyl groups.

19. The process ofnitrating a sugar which comprises the addition of analkyl ester of a saturated hydroxy aliphatic carboxylic acid containingnot more than two carboxyl groups, to a mixed acid consisting of roughly60% nitric acid and 40% sulfuric acid followed by the addition of thesugar, maintaining the temperature of the mixture below 30 C. andseparating nitrated products from the spentacid.

20. The process of nitrating a sugar which comprises the addition ofethyl lactate to a mixed acid, roughly 60% nitric acid and 40% sulfuricacid, followed by the addition of the sugar, maintaining the temperatureof the mixture below 30 C., and separating nitrated products from thespent acid.

10 lected from the group of ethyl alcohol, propyl alcohol, propane,butane, pentane, benzene, gasoline, hexane, heptane, carbontetrachloride and chloroform. V

22. The process of nitrating a member of the 'group consisting of canesugar, glucose, levulose,

lactose, and their glycosides in the presence of an alkyl ester of asaturated hydroxy aliphatic carboxylic acid containing not more than twocarboxyl groups.

JOSEPH A. WYLER. 10

